I've had a slingbox for years, typically accessing it remotely through my home gateway server proxied through ssh.

Today, I finished setting up a site-to-site VPN (using Sonicwall routers) to connect two LANs that I control. Everything is working fine in both directions EXCEPT for my Slingbox. I am able to access the actual box, i.e, I can see the configuration, was even able to change bits of it, but when I try to actually watch something, it (says that it) connects, 1 item pending, etc, etc, and then it just disconnects ("No connection")

Anyone have any idea how to deal with this? There's no VPN client involved in this setup so the existing instructions I found on the website don't apply.